Mattresses and futons have long been held together by means of tufts. The tuft also serves to stabilize the outer layers of materials, tickings and fillings.
In the art, the word ‘tuft’ is generally understood to comprise two elements (hereinafter known as ‘tuft elements’) located outside each principal face of the mattress, and held together by means of a cord, strip or similar device (hereinafter referred to as a ‘retaining link’), attached to each tuft element. Hereinafter the word ‘tuft’ when used alone will be used to describe the complete arrangement of tuft element, retaining link and further features.
One particular type of tuft known in the art is the “tape tuft” 22 illustrated in FIG. 1. This tuft comprises a strip 12 of flexible material (typically nylon, although polyethylene, polypropylene, rayon and other materials may also be used) which interacts at either end with tuft elements 14a, 14b of harder material (polymers such as nylon, polyethylene and polypropylene being preferred, although other materials such as metal and wood may also be used). Similar tufts are described in, for example, UK Patent 814651, although the tuft elements described in this patent are made of different material.
Tape tufts may advantageously be produced by molding. As illustrated in FIG. 1, a string 10 of tufts 22, 24, 26 joined in series and comprising a continuous strip 12 interacting with tuft elements 14a, 14b, 14c, 14d, 14e, may be produced. The string of tufts may typically be provided on a reel or the like: the tufts are separated by cutting the strip between the tuft elements. Alternatively, the string could be supplied pre-cut into individual tufts, which are then loaded into a magazine or the like.
Typically, such tape tufts are attached to the mattress using a needle, such as a tufting or ejector needle, the structure of which is well known to those skilled in the art. An example of a tufting needle is given in UK Patent 903464, the contents of which are incorporated herein by reference thereto.
The mattress is first compressed to a thickness less than the length of the tape tuft to be used. One of the tuft elements is inserted into a recess in the tufting needle, leaving the other end free. The tufting needle, carrying the first tuft element, is then passed through both faces of the mattress, the second (free) tuft element being unable to pass through the hole made by the needle and consequently remaining outside the mattress. When the tufting needle exits the mattress, the first tuft element is released so that both tuft elements are located on the outside faces of the mattress. The tufting needle may further be provided with elastic means, such as a spring-loaded plunger, which ejects or otherwise aids release of the first tuft element from the tufting needle. Once the tufting process is complete, the mattress is decompressed.
Many manufacturers use a support, such as a washer, in connection with the tape tuft; a support may be provided on either or both faces of the mattress. The function of such supports is to prevent the tuft element from being pulled through the mattress ticking and to make the tuft more comfortable to sit or lie on. Such supports may be made from felt, cardboard, foam, leather or plastic. A first washer may be fitted to the proximal face of the mattress (i.e. the face the needle enters) by attaching it to the free tuft element, the washer being unable to pass through the mattress. When the needle emerges from the distal face of the mattress, its point may engage a second washer so that when the first tuft element is released from the tufting needle, the washer need only be disengaged from the needle point to be in the correct position. Alternatively, the second washer may be placed on the tuft element after it has been ejected from the tufting needle, before the mattress is decompressed.
The tufting method described hereinabove has traditionally been carried out manually. The operator may have to apply a considerable amount of force to drive the tufting needle through the mattress. This makes the process slow and inefficient, and repeatedly applying such forces over a long period of time may be detrimental to the health of the operator.
It would therefore be desirable to increase automation of the tufting process, making the process faster and more efficient, and less reliant on manual effort.
Machines which allow the tufting needle to engage with driving means, such as a pneumatic piston or mechanical jack, are known in the art. The first tuft element is engaged with a recess on the tufting needle as described hereinabove, and the needle is then connected to, or forms part of, means which drive the needle through the mattress. An example of such a machine is described in UK Patent 914253.
However, while such machines automate some steps of the tufting process, a significant amount of manual input is still required. In particular, it remains necessary to load the tuft element manually. It would therefore be desirable to provide a device and method which minimizes manual input.
In particular, it would be advantageous to provide a device capable of tufting a mattress using the string of tufts described above, without the operator having to stop the device after fitting a tuft to separate the next tuft from the string.
It would further be advantageous to provide a device which aids the release of the tuft element from the tufting needle.
In addition, it would be desirable to provide a device capable of automatically placing the supports (such as washers) in their correct positions.